In the manufacture of batteries, particularly for example lead acid batteries, it is known to cast connectors known as “straps” and other formations onto the “lugs” (or “tabs”) of battery plates. For example, straps are formed to provide a connection between a set of plates within a cell of the battery. Straps are generally cast using a “cast on strap machine” in which a mould cavity is filed with molten metal (normally molten lead) before the lugs of a group of battery plates are dipped into the cavity prior to the cooling of the lead. The mould for forming such straps general comprises a plurality of cavities each configured to form a separate strap across a “pack” or “group” comprising a plurality of battery plates. The mould may for example include a series of generally paired cavities spaced along the length of the mould such that each pair of cavities can form a positive and negative strap for a single group of batteries (and with the mould, therefore, forming a plurality of groups spaced along the length in a single process).
Typically, the mould cavities are filled by allowing lead to flow into channels at the sides of the cavities and spill over a weir into the mould. An example of such a moulding apparatus is shown in the Applicant's earlier published PCT Application WO94/16466. In order to ensure a good connection between the lugs and casting, the lead must remain hot until the lugs are in position. However, in order to minimise cycle time in production, the lead must be cooled as quickly as possible once the plates are in position.
It is important that the volume of lead is carefully controlled during strap casting as excess lead (for example as a result of mould features such as weirs) will have an impact on both the cost and weight of the final battery produced.
As such, the Applicants have recently proposed a new battery moulding apparatus in published UK Patent Application GB2507485. In this arrangement a reciprocating sliding block is used to provide an accurately measured volume of lead for each cavity of a mould.
Embodiments of the invention seek to provide further improvements over the arrangement proposed in GB2507485 which may for example, further reduce the cycle time and/or further improve consistent measuring of lead and/or provide delivery of lead with minimal cooling during transit to the mould and/or provide improved ease of maintenance or usage of the apparatus.